There is known, from U.S. Pat. No. 1,832,734, a clasp including a cover and two push-pieces whose axis of travel does not coincide with the hinge axis of the cover. However, application of pressure on a single push-piece accompanied by simultaneous application of pressure on one side of the cover opposite the push-piece opens the clasp, which is absolutely unacceptable in the eyes of the Applicant of the present invention.
There is also known, from EP Patent No 0913106, a folding clasp including a rigid base provided with two side members, a cover arranged to be attached to a bracelet strand, and at least one folding arm having a rear end attached to one end of the base by a first hinge and having a front end attached to the cover by a second hinge. The folding arm includes two juxtaposed branches provided with push-pieces, and whose front ends are held apart by an elastic element. Such a clasp has the same aforecited drawback: the cover has too much play, thus allowing the clasp to be opened by application of pressure on a single push-piece accompanied by simultaneous pressure on one side of the cover opposite the push-piece.